A Closer Look at Fish Oil Research

A recent article in the Washington Post questions the health benefits of taking fish oil supplements, and reports on research that seems to indicate that fish oil does not reduce the risk of heart disease. However, the body of research on fish oil is more complicated than the Washington Post article suggests and includes some compelling evidence of fish oil's benefits. Here is a closer look at that body of research:

A 2012 meta-analysis of 20 studies, published in JAMA, found that fish oil supplements were associated with a 4% lower risk of all-cause mortality and a 9% lower risk of cardiac death, although the decreases were not statistically significant.

However, a subpopulation of patients within the meta-analysis—over 11,000 people who had recently had a heart attack and were taking fish oil—had a 20% lower risk of all-cause mortality and a 30% lower risk of cardiovascular death, compared with the placebo group.

While the 2012 meta-analysis did not find statistically significant differences between the placebo and fish oil groups overall, it may have included flawed studies that skewed the results. For example, the meta-analysis included a very large study that enrolled over 18,000 men and women in Japan: this study did not find a beneficial effect of fish oil on heart health. Yet, because Japanese consumption of seafood is so high to begin with, it was unlikely that the addition of fish oil supplements would improve heart health considerably.

Further, much of the recent research on fish oil has involved high-risk populations. These populations may have had health that was declining too rapidly for fish oil to make a considerable difference, as opposed to generally healthy populations who may have seen a preventative effect from taking fish oil.

Finally, as the Washington Post article discusses, many studies on heart health and fish oil have included patients taking heart medications. Many of these medications, such as statins (often prescribed for high cholesterol), have an anti-inflammatory effect in the body, like fish oil. Therefore, taking fish oil with statins may leave little room for fish oil to have a noticeable anti-inflammatory effect.

The bottom line? Despite receiving some negative press, fish oil supplements may offer some important benefits, with only limited side-effects confirmed to date. In particular, the bulk of the evidence suggests that fish oil supplements can improve heart health in people who are not regular fish eaters and who are not taking statin drugs. Studies have also shown that fish oil may strengthen the immune system and help with a wide range of other health issues, including some dermatological, gastrointestinal, neurological, and psychiatric conditions. Of course, always consult a healthcare professional before starting a new supplement regimen.